Fluorinated aldehyde containing polymers

ABSTRACT

Fluorinated aldehydes are made by reacting a fluorinated acyl chloride with a silicon hydride in the presence of palladium. Also disclosed are fluorinated ether aldehydes and their polymers, a process for making fluorinated aldehydes polymers using titanium or aluminum alkoxide catalysts, and a process for endcapping fluorinated polymers using perfluoroallyl fluorosulfate or fluorine.

This is a division of Ser. No. 07/823,211, filed Jan. 21, 1992, now U.S.Pat. No. 5,414,140.

FIELD OF INVENTION

This invention concerns a process for the manufacture of fluorinatedaldehydes by the palladium catalyzed reaction of a silicon hydride witha fluorinated acyl chloride. Also disclosed are perfluorinated etheraldehydes and their polymers, a process for polymerizing fluorinatedaldehydes, and processes for endcapping fluorinated aldehyde polymers.

BACKGROUND OF THE INVENTION

Fluorinated aldehydes and their polymers are known in the art, see forexample U.S. Pat. No. 2,568,500, of Husted et al. issued Sep. 18, 1951;U.S. Pat. No. 2,828,287 of Cairns et al. issued Mar. 25, 1958, and areview article on fluoroaldehyde polymers, K. Neeld and O. Vogl., J.Polym. Sci., Macromol. Rev., vol. 16, p. 1-40 (1981). Fluorinatedaldehydes form polymers that are useful as chemically and thermallyresistant elastomers and thermoplastics, useful for making parts thatrequire these .properties, and for films and coatings. Fluorinatedaldehydes have been made by a variety of methods.

U.S. Pat. No. 3,067,173 of Barney issued Dec. 4, 1962, discloses varioushalogenated polyacetals. These polymers contain halogenated β-alkoxygroups. β-alkoxypolyfluoroaldehydes are used in their preparation.

J. D. Citron, J. Org. Chem., vol. 34, p. 1977-1979 (1969), reports thatacyl chlorides react with silicon hydrides in the presence of palladiumto form aldehydes. No mention is made of the formation of fluorinatedaldehydes.

German Patent 3,640,178 A1 published June 6, 1988 describes thesynthesis of fluorosubstituted aldehydes by the reaction of fluoroacylfluorides with silicon hydrides in the presence of palladium or apalladium complex. The use of fluoroacyl chlorides is not mentioned.

J. D. Citron, J. Org. Chem., vol. 36, p. 2547-2548 (1971) reports thatacyl fluorides do not react with silicon hydrides in the presence ofpalladium. However, a reaction to produce an ester does occur when anacyl fluoride and a silicon hydride are heated together.

U.S. Pat. No. 3,208,975 reports that various chelated aluminumcompounds, some of which contain alkoxides, catalyze the polymerizationof various aldehydes, including trifluoroacetaldehyde. No mention ismade of using aluminum compounds containing fluorinated alkoxides.

This invention provides a process for making fluorine substitutedaldehydes from available starting materials, particularly making themsufficiently pure so as to be readily polymerizable. This invention alsoprovides novel fluorinated aldehydes and their polymers, a process formaking fluorinated aldehyde polymers, and a method for endcappingfluorinated aldehyde polymers.

SUMMARY OF THE INVENTION

This invention provides a process for the production of fluorinatedaldehydes, comprising, contacting finely divided palladium, a siliconhydride of the formula (R⁵)₃ SiH, and an acyl chloride of the formula##STR1## wherein:

R¹ is fluorine, perfluoroaryl or R³ R⁴ CF--;

R² is fluorine, perfluoroaryl ##STR2##

R³ and each R⁴ are independently fluorine, hydrocarbyl, or substitutedhydrocarbyl; and

each R⁵ is independently alkyl, to yield a fluorinated aldehyde offormula ##STR3## wherein:

R¹ and R² are as defined above.

This invention also comprises an aldehyde of the formula

Y(CX₂ CX₂ O)_(k) (C₃ F₆ O)_(m) (CF₂ O)_(n) (CX₂)_(p) CF₂ CHO

wherein:

Y is fluorine, aryloxy or --OCF═CF₂ ;

each X is independently hydrogen or fluorine;

p is 0 or 1; and

k, m and n are each independently zero or an integer of 1 to 50;provided that k+m+n is 2 or more.

This invention also comprises a polymer, comprising the repeat unit##STR4## wherein:

Y is fluorine, aryloxy or --OCF═CF₂ ;

each X is independently hydrogen or fluorine;

p is 0 or 1; and

k, m and n are each independently zero or an integer of 1 to 50;provided that k+m+n is 2 or more.

This invention also provides a process for the polymerization offluorinated aldehydes comprising contacting an aldehyde of the formulaACHO with a titanium (IV) compound or an aluminum (III) compound inwhich one or more alkoxy groups are bound to the titanium or aluminumatom, wherein:

A is perfluoroaryl or R⁶ R⁷ FC--;

R⁶ is fluorine, perfluoroaryl, perfluoroalkyl, or ether substitutedperfluoroalkyl; and

R⁷ is fluorine, hydrogen or substituted alkyl; provided that the initialmolar ratio of said aldehyde to said titanium or aluminum compound is nomore than about 50,000 to 1, and further provided that for the aluminumcompound, the alkoxide groups each contain at least one fluorine atom.

This invention also provides a process for endcapping a fluorinatedaldehyde polymer comprising contacting a fluorinated aldehyde polymer,which is capable of further polymerization, with perfluoroallylfluorosulfate or fluorine, provided that when endcapping withperfluoroallyl fluorosulfate the polymer is formed by anionicpolymerization.

DETAILS OF THE INVENTION

This invention concerns a process for the preparation of an aldehyde ofthe formula ##STR5## comprising contacting an acyl chloride of theformula ##STR6## with a silicon hydride of the formula (R⁵)₃ SiH in thepresence of finely divided palladium wherein R¹, R², and R⁵ are asdefined above. The silicon hydride reacts with the acylchloride,reducing the acyl chloride to the corresponding aldehyde.

In a preferred acyl chloride (and in the product aldehyde) R¹ isfluorine. In another preferred acyl chloride R¹ is R³ R⁴ CF--, and R²and R³ are fluorine; it is more preferred if in addition R⁴ isperfluoroalkyl; and especially preferred if R⁴ is perfluoro-n-alkyl. Inanother preferred acyl chloride R² is fluorine and R¹ is R³ R⁴ CF--wherein R³ is fluorine and R⁴ is CF₃ --, n--C₅ F₁₁ --, CF₂ ═CFOCF₂CF(CF₃)O--, CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)O--, or CF₃ CH₂ O--. In anotherpreferred embodiment R¹ is R³ R⁴ CF-- wherein R³ and R⁴ are bothfluorine, and R² is CF₃ CF₂ CF₂ O--. A preferred perfluoroaryl group ispentafluorophenyl.

Substituted hydrocarbyl includes, but is not limited to linear, branchedor cyclic alkyl, alkenyl, alkynyl, dienyl, or aryl of 1 to 20 carbonatoms substituted with one or more of ether, fluorine, chlorine,bromine, cyano and alkoxycarbonyl substituents. Preferred substituentsare fluorine and ether, and fluorine is especially preferred. When etheroxygens are present, they are present between carbon atoms in the acylchloride (and product aldehyde).

The silicon hydride, (R⁵)₃ SiH, reduces the acyl chloride to thefluorinated aidehyde. In preferred silicon hydrides, each R⁵ contains 1to about 20 carbon atoms, preferably 1 to 4 carbon atoms. In preferredsilicon hydrides, every R⁵ is isopropyl or ethyl, and isopropyl is morepreferred.

The palladium metal used in the process is present in finely dividedform. Usually, and preferably, it will be on a support such as carbon(charcoal). Carbon is a preferred support. Such supported metals arewell known to those skilled in the art and are commercially available. Apreferred concentration is about 2 to 10% by weight of the metal on thesupport. Finely divided palladium metal may be made according to theprocess described in J. D. Citron, et al., J. Org. Chem., vol. 34, p.638-640 (1969).

The process of the present invention can be carried out in the presenceof an inert solvent, such as a fluorohydrocarbon solvent, however, it ispreferred to carry out the process in the absence Of solvent. Some typesof compounds that may act as solvent can complex with fluorinatedaldehydes, but fluorinated aldehydes are best polymerized when they arenot complexed. It is sometimes difficult to isolate the fluorinatedaldehyde from its complexes, so a solventless process which producespure fluorinated aldehyde is preferred.

The process of the present invention is conducted at any convenienttemperature at which the starting materials and products are stable.However, it is preferred that the-process temperature be about -20° C.to about +50° C., preferably about -10° C. to about 30° C. The processis conducted at ambient pressure.

The presence of compounds containing active hydrogen atoms, such aswater (moisture), alcohols, primary and secondary amines, etc., shouldbe avoided, since these compounds may react with the acyl chlorideand/or silicon hydride, and may also complex with the fluorinatedaldehyde product. A convenient way to exclude these materials is to usean inert atmosphere, such as nitrogen or argon.

Although not necessary, it is preferred to agitate the process mixtureto speed the reaction. The product slurry contains the palladium,chlorosilane, and fluorinated aidehyde. The desired aldehyde may beobtained by filtering or distilling the organic compounds from thepalladium, and then distilling or separating the resulting mixture ofchlorosilane and fluorinated aldehyde to obtain the pure aidehyde. Sucha procedure permits no contact with compounds that may complex thefluorinated aidehyde. Other methods of isolating the fluorinatedaldehyde will be apparent to the art skilled and are also illustrated inthe Examples.

Although almost any molar ratio of silicon hydride to acyl chloride maybe used, in order to use the ingredients most efficiently, anapproximately 1:1 molar ratio is preferred, although sometimes a smallexcess (up to about 25%) of silicon hydride will give a slightly betteryield. The ratio of palladium to the other reactants is not critical,about 0.001-0.01 gram atoms of palladium per mole of acyl chloride beinga convenient range.

The process of the present invention is useful in making fluorinatedaldehydes. The fluorinated aldehydes made by the instant invention areuseful as monomers for making polymers. The resultant polymers areuseful in films and coatings, particularly where solvent and heatresistance is required.

Also included in the present invention is an aldehyde of the formula

Y(CX₂ CX₂ O)_(k) (C₃ F₆ O)_(m) (CF₂ O)n(CX₂)_(p) CF₂ CHO

wherein p is 0 or 1; each X is independently hydrogen or fluorine; Y isfluorine, aryloxy or --OCF=CF₂ ; and k, m and n are each independentlyzero or an integer of 1 to 50; provided that k+m+n is 2 or more. Thealdehydes can be prepared using the above described process of palladiumcatalyzed reaction of a silicon hydride with a fluorinated acylchloride. Specific details are exemplified herein in Examples 6, 8 and11. The fluorinated acyl chlorides are prepared from acyl fluorides asdescribed below under the section titled "Starting Material.Preparations". The acyl fluorides can be made by methods described inU.S. Pat. Nos. 3,665,041 and 4,664,766. The aldehydes are useful toprepare polymers useful as chemically and thermally resistant elastomersand thermoplastics, employed in making parts that require theseproperties, and for films and coatings.

The aldehydes described in the immediately preceding paragraph arepolymerized to form polymers comprising the repeat unit ##STR7## whereinp is an integer of 0 or 1; Y is fluorine, aryloxy or --CF=CF₂ ; each Xis independently fluorine or hydrogen; and k, m and n are eachindependently zero or an integer of 1 to 50; provided that k+m+n is 2 ormore. These polymers are made as described below for the polymerizationof fluorinated aldehydes by contacting the aldehyde with a titanium (IV)compound or an aluminum (III) compound substituted with one or morealkoxy groups, or by other methods known to those skilled in the art,see for instance, K. Neeld and O. Vogl, J. Polym. Sci., Macromol. Rev.,vol. 16, p. 1-40 (1981), which is hereby incorporated by reference.Specific details are exemplified in Examples 8-12 herein. These polymersare homopolymers containing only the above enumerated repeat unit, orare copolymers containing the above repeat unit with repeat unitsderived from other aldehydes. These polymers are useful as chemicallyand thermally resistant elastomers and thermoplastics, useful for makingparts that require these properties, and for films and coatings.

This invention also provides a process for the polymerization offluorinatedaldehydes comprising contacting an aldehyde of the formulaACHO with a titanium (IV) compound or an aluminum (III) compound inwhich one or more alkoxy groups are bound to the titanium or aluminumatom, and wherein: A is perfluoroaryl or R⁶ R⁷ FC--; R⁶ is fluorine,perfluoroaryl, perfluoroalkyl, or ether substituted perfluoroalkyl; andR⁷ is fluorine, hydrogen or substituted alkyl. This polymerization maybe carried out with or without solvent present, but it is preferred ifsolvent is absent. Suitable solvents include, but are not limited to,ether, chlorofluorocarbons, and hydrofluorocarbons.

The polymerization is carried out at about -50° C. to about 75° C.,preferably 0° C. to 50° C. and more preferably about 10° C. to 30° C.The process ingredients should be dry, and care should be taken toexclude moisture, as by performing the polymerization under an inert gassuch as nitrogen. For best results, the monomer should be stored at lessthan 0° C. before use, preferably in a polytetrafluoroethylenecontainer. The polymer may be isolated by evaporation of the solvent andother volatiles, or if solid, by filtration.

The initial molar ratio of aidehyde to metal alkoxide is from about50,000 to 1 to about 50 to 1, preferably from about 10,000 to 1 to about100 to 1, and more preferably from about 5,000 to 1 to about 250 to 1.

The titanium (IV) and aluminum (III)-compounds used in the process haveat least one alkoxy group bound to the metal atom. The alkoxy group maybe substituted with various substituents such as chloro, bromo, cyano,fluoro, ether and other inert substituents. Fluoro is a preferredsubstituent for the alkoxy group in the titanium compound and isrequired in each alkoxy group in the aluminum compound. The presence offluorine in the alkoxy groups makes the polymerization catalyst moresoluble in highly fluorinated aldehydes, and gives smootherpolymerizations. The titanium compound may have one to four alkoxygroups, but one is preferred. When there are less than four alkoxygroups other ligands that can form stable bonds to titanium (IV) may bepresent, such as a triethanolamine ligand N(CH₂ CH₂ O--)₃ !. By titanium(IV) is meant titanium in the +4 state. Preferred alkoxy groups for thetitanium compounds are isopropoxide, CF₃ CH₂ O--, (CF₃)₂ CHO--, and CF₂═CFOCF₂ CF(CF₃)OCF₂ CF₂ CH₂ O--. A preferred alkoxy group for thealuminum compound is CF₃ CH₂ O--.

Preferred is the polymerization process wherein the titanium (IV)compound is GTiJ wherein G is isopropoxide, CF₃ CH₂ O--, (CF₃)₂ CHO--,or CF₂ ═CFOCF₂ CF(CF₃)OCF₂ CF₂ CH₂ O--, and J is N (CH₂ CH₂ O--)₃.

This process using a titanium or aluminum alkoxide to polymerize afluorinated aldehyde results in rapid polymerization of the aldehyde toform essentially linear polymers. These linear polymers are useful aschemically and thermally resistant elastomers and thermoplastics, formaking parts requiring these properties, and for films and coatings.

This invention also provides a process for endcapping a fluorinatedaldehyde polymer comprising contacting a fluorinated aldehyde polymerwhich is capable of further polymerization, with perfluoroallylfluorosulfate or fluorine, provided that when endcapping withperfluoroallyl fluorosulfate the polymer is formed by anionicpolymerization. It is well known that polymers of aldehydes,particularly fluorinated aldehydes, tend to "unzip" or depolymerize tomonomers under a variety of Conditions, including thermally, and acidand base catalysis. In order to isolate the polymers of fluorinatedaldehydes before unzipping takes place, it is preferred to "endcap" thepolymer with a group that prevents unzipping. The choice of endcappinggroup will affect the thermal stability of the polymer.

Thus endcapping is carried out on a fluorinated aldehyde polymer whichis capable of further polymerization. By that is meant that the group onthe end of the polymer causes further polymerization if more aldehyde isadded. This group is sometimes referred to as the polymer living end. Inaddition when perfluoroallyl fluorosulfate is used to endcap thepolymer, the polymer is formed by anionic polymerization. Anionicpolymerization includes the use of catalysts such as fluoride ion,fluorosilicates, and alkali metal alkoxides. Endcapping withperfluoroallyl fluorosulfate or fluorine gives polymers that arerelatively thermally stable.

The endcapping may be carrier out at any temperature at which thereactants are stable, but it is preferably carried out at about 0° C. toabout 30° C., which is the temperature at which the fluorinatedaldehydes are typically polymerized. The perfluoroallyl fluorosulfate orfluorine is simply added to and mixed with the polymerization mixtureafter the polymer is formed. No compound which reacts withperfluoroallyl fluorosulfate or fluorine should be present in thepolymerization mixture other than the polymer ends.

Typical times for complete endcapping are about 1 to 24 hr withperfluoroallyl fluorosulfate. In order to ensure complete endcapping itis preferred to use a large excess of the perfluoroallyl fluorosulfate,at least about 100 moles of the fluorosulfate per mole of polymer to beendcapped. Lesser ratios may be used, but longer reaction times and/orincomplete capping may result. Due to the end cap derived from theperfluoroallyl fluorosulfate or fluorine, the resulting endcappedpolymers are also included in the present invention.

When using fluorine to endcap the polymer, usually a mixture of fluorineand an inert gas such as nitrogen will be used, for example 80 volumepercent nitrogen and 20 volume percent fluorine, at a pressure of about1×10⁵ to 13×10⁵ Pa. Fluorine resistant reactors, such as those made ofHastelloy®, should be used. After the reaction is complete, excessfluorine and other byproducts can be removed by washing with sodiumbicarbonate solution. It is preferred if the endcapping with fluorine isdone without added solvent.

In the Examples the following abbreviations are used:

DSC--differential scanning calorimetry

F11--fluorotrichloromethane

F113--1,1,2-trichloro-1,2,2,-trifluoroethane

glyme--1,2-dimethoxyethane

Mn--number average molecular weight

MW--molecular weight

Mw--weight average molecular weight

TASF--tris(dimethylaminosulfonium) trimethyldifluorosilicate

TGA--thermogravimetric analysis

THF--tetrahydrofuran

Starting Material Preparations

PREPARATION OF CF₃ CF₂ CF₂ OCF (CF₃)COCl

A mixture of AlCl₃ and o-dichlorobenzene (4 mL) was treated with CF₃ CF₂CF₂ OCF(CF₃)COF(13.2 g, 40 mmol) and heated at 60° C. for 0.5 hr..Volatiles were removed by vacuum transfer (27 Pa) to give a mixture oftwo liquids. The lower layer was separated and distilled to provide 8.0g of colorless liquid, bp ca. 65° C. GC analysis showed 99% purity. 19FNFIR (F11): -81.32 (s, CF₃), -81.94 (t, J=7.3 Hz, CF₃), -79.05 and-84.98 (AB pattern, J=146 Hz, OCF₂), -126.1 (d of m's, J=23, CF), -130.1(s, CF₂) .

PREPARATION OF CF₃ CH₂ OCF₂ CF₂ C(O)OCH₃, CF₃ CH₂ OCF₂ CF₂ C(O)ONa, ANDCF₃ CH₂ OCF₂ CF₂ C(O)OK

The methyl ester was prepared according to the method described inliterature: Krespan et al., J. Am. Chem. Soc., 106, 5644 (1984), whichis hereby incorporated by reference.

The sodium and potassium salts of the acid were prepared according toprocedures described by E. D. Laganis and B. L. Chenard, TetrahedronLetters, 25, 5831 (1984), which is hereby incorporated by reference.

PREPARATION OF CF₃ CH₂ OCF₂ CF₂ C(O)Cl

A 3-necked round bottom flask fitted with a reflux condenser andmechanical stirrer was charged with CF₃ CH₂ OCF₂ CF₂ C(O)OK (14.2 g, 50mmol). Oxalyl chloride (6.34 g, 50 mmol) was added dropwise at a ratesuitable to control the exotherm and evolution of gas. When gasevolution had ceased, the mixture was heated at 80° C. for 1.0 hr.Volatiles were removed under vacuum (27 Pa) to give 12.1 g of colorlessliquid (93%) homogeneous by GC. IR (CCl₄): 1803 cm⁻¹. (C=O). ¹ H NMR(CD₂ Cl₂): 4.42 (q, J=7.5 Hz). ¹⁹ F NMR: -74.85 (tt, 7.7, 2.3, CF₃),-87.1 (m, OCF₂), -116.27 (t, J=4.5, CF₂). GC/MS featured. observed m/zat 199. 0028; calcd. for C₄ H₂ OF₇ (M-C (O)Cl)=198.9994.

PREPARATION OF CF₃ CH₂ OCF₂ CHFOCF₂ CF (CF₃) OCF₂ CF₂ C (O) OCH₃

Oil-free sodium hydride (150 mg) was. treated with DMF (30 mL) andcooled to 0° C. Trifluoroethanol (10.9 g, 110 mmol) was added, and themixture was allowed to warm to 25° C. A 30.0 g (71 mmol) sample of CF₂═CFOCF₂ CF(CF₃)OCF₂ CF₂ CO₂ CH₃ was added. GC analysis revealed thatlittle reaction had occurred, so an additional 2.2 mL oftrifluoroethanol and 0.2 g sodium hydride dispersion were added. Afterthe exotherm subsided, the mixture was stirred for 6 hr, poured intowater (150 mL), neutralized with HCl, and extracted with 1, 1,2-trichloro-1,2,2-trifluoroethane. The organic layer was washed fourtimes with water, dried, and stripped to give 52.2 g of residue.Kugelrohr distillation provided 34.6 g, bp 44°-54° C./7 Pa (94%). ¹ HNMR (THF-d₈): 6.72 (d of m's, J=52 Hz), 4.63 (q, J=8), 3.97 (s) . 19FNMR: -74.77 (t, J=8.2, CF3), -79.99 and -80.83 (overlapping t, J=9),-82.0 to -85.3 (overlapping AB patterns, 4F), -90.0 and -90.5 (ABpattern, J=149), -121.35 (m), -145.0 (m) , -145.87 (d of m's),consistent with the desired ester.

PREPARATION OF CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ C(O)OK

A suspension of potassium trimethyl silanoate (9.6 g, 75 mmol) in ether(150 mL) was treated with CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ C(O)OCH₃(39.5 g, 76 mmol) prepared as described above and the mixture wasstirred for 18 hr. Since the product was quite soluble, the solvent wasremoved under vacuum to give 40.4 g of white solid. ¹ H NMR(acetone-d6): 6.80 and 6.83 (d of t's, J_(d) =52, J_(t) =3.4 for twodiastereomers), 4.71.and 4.70 (overlapping quartets, J=8.5). ¹⁹ F NMR:-74.2 (t, J=8.4 ), -7 9.3 (m), -80.5 to -85.5 (overlapping AB's), -89.4(center of overlapping AB patterns), -118.13 and -118.19 (CF₂ CO₂singlets), -144.5 to -145.7 (overlapping m's), consistent with thedesired structure.

PREPARATION OF CF₃ CH₂₀ CF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ C(O)Cl

A 3-necked round bottom flask equipped with a reflux condenser, nitrogeninlet, and mechanical stirrer was charged with CF₃ CH₂ OCF₂ CHFOCF₂CF(CF₃)OCF₂ CF₂ C(O)OK (37.9 g, 69 mmol) prepared as described above.Oxalyl chloride (8.8 g, 69 mmol) was added dropwise at a rate tomaintain the temperature below ca. 35° C. and to allow for gasevolution. When the addition was complete, the mixture was heated to 80°C. for 1.25 hr. volatiles were transferred under vacuum (13 Pa) whilethe pot was maintained at 80° C. Product was purified by spinning banddistillation (17 mm) to give 29 g of desired acid chloride, obtaining16.8 g as a center cut with bp 78° C. ¹ H NMR (CDCl₃): 5.98 (d of t's,J=52, 3.5 Hz), 4.32 (q, J=8 Hz). ¹⁹ F NMR: (CD₂ Cl₂ /F11): -75.08 (t,J=7.9), -80.3 (m), -81.6 (m), Overlapping AB patterns -83.44 and -85.74(J=145) and -83.77. and -86.08 (J=150), -90.01 and -90.88 (AB pattern,J=143, with small shift differences for the diastereomers), -116.5(overlapping doublets, J=3.5), -145.1 (m, overlapping signals fortertiary CF and CHF moleties).

EXAMPLE 1 PREPARATION OF C₇ F₁₅ CHO

A sample of triethylsilane (4.24 g, 36.5 mmol) was cooled to 0° C. andtreated with 10% Pd/C (0.35 g) . After the exotherm subsided,perfluorooctanoyl chloride (15.8 g, 36.5 mmol) was added dropwise,controlling the temperature below ca. 6°-8° C. The mixture was stirredfor 1.0 hr at 0° C., Another 0.59 g triethylsilane was added, and themixture was stirred for 1.5 hr. An additional 0.13 g of triethylsilanewas added. After 1.0 hr, vacuum transfer gave 16.4 g of liquid which wascooled at -25° C. for several hours. The top liquid layer was removedfrom the solid to provide ca. 10.5 g of the titled product. 19F NMR:-81.3 (t of t's, J=9.8, 2.3), -121.8 (m), -122.3 (m), -123.0 (m), -123.7(m), -125.4 (t of m's, with J_(FCCH) =3 Hz), -126.5 (m).

EXAMPLE 2 PREPARATION OF C₇ F₁₅ CHO

Catalyst 10% Pd/C (200 mg) was placed in a 3-necked round bottom flaskand cooled at 0° C. Triisopropylsilane (3.32 g, 21 mmol) was added,followed by perflurooctanoyl chloride (7.9 g, 18.2 mmol). The mixturewas allowed to warm to room temperature and was then controlled at25°-27° C. during the exothermic reaction. After 3 hr, GC analysisshowed aidehyde/acid chloride ratio=94/6. Another 0.26 mL of silane wasadded and stirring was continued for 1 hr. Vacuum transfer gave liquidwhich was chilled at -25° C. The resulting solid was shaken Withpetroleum ether, chilled at -25° C. and separated again. In this way,6.48 g of product was obtained, mp ca. -5° C. NMR spectra were asdescribed in Example 1.

EXAMPLE 3 PREPARATION OF C₃ F₇ CHO

A 3-necked round bottom flask fitted with with dropping funnel, dry-icecondenser, and gas inlet was charged with 10% Pd/C (0.35 g) and cooledto 0° C. Triisopropylsilane (7.29 g, 46 mmol) was added, and CF₃ CF₂ CF₂C(O)Cl (9.30 g, 40 mmol) was added dropwise over a 10 min period. Thereactor was connected to a cold trap (-78° C.) while the mixture wasstirred for 18 hr. Transfer from the trap and reaction vessel gave atotal of 5.1 g (62%) of colorless liquid. ¹ H NMR (CD₂ Cl₂): 9.62 (m).19F NMR: -81.24 (t, J=8.3 Hz), -126.4 (quartet of doublets, J_(q) =8.3,J_(d) =3.2), -127.9 (s).

EXAMPLE 4 PREPARATION OF CF₃ CF₂ CF₂ OCF(CF₃)CHO

A 3-necked round bottom flask equipped with a dropping funnel and refluxcondenser was charged with 10% Pd/C (0.35 g) and cooled to 0° C.Triisopropylsilane (6.0 g) was added. CF₃ CF₂ CF₂ OCF(CF₃)COCl (10.9 g)was added, and the mixture was stirred at 25° C. for 75 hr. During thisperiod, a total of 0.5 g of additional catalyst was added in ca. 0.1 gincrements. Vacuum transfer and separation of the lower layer afterchilling at -25° C. provided 5.26 g of liquid. ¹ H NMR (THF-d₈ /F11):9.9 (m). 19F NMR: -79.4 (m), -81.1 (s), -81.4 (t, J=7.2), -129.5 (s),-138.8 (m). ¹ H-decoupling experiment showed J_(HCCF) ca. 2.5 Hz.

EXAMPLE 5 PREPARATION OF CF₂ =CFOCF₂ CF(CF₃)OCF₂ CF₂ CHO

A 3-necked round bottom flask equipped with addition funnel andcondenser was charged with 10% Pd/C (0.53 g) and cooled in an ice bath.Triisopropylsilane (8.1 g, 51 mmol) was added, and CF₂ ═CFOCF₂CF(CF₃)OCF₂ CF₂ COCl (17.3 g, 41 retool) was added dropwise over 25 min.The mixture was warmed to 25° C. and the exotherm was controlled by a25° C. water bath. The mixture was stirred for 18 hr, and product wastransferred from the reactor at 67 Pa. The liquid so obtained waschilled at -25° C. and the lower layer was separated and washed severaltimes with petroleum ether. Layer separations were carried out at ca.-20° C. to -25° C. There was obtained 7.9 g (49% isolated) of desiredproduct. ¹⁹ F NMR (C₆ D_(6/) F11): -80.3 (m, CF₃), -82.2 (m, OCF₂),-85.0 (m, OCF₂), -113.5 (dd, J=66, 83 Hz, vinyl CF) , -121.9 (dd oftriplets,. Jr=5.1, J_(d) =83, 113 Hz, vinyl CF), -127.6 (d, J=2.3, CF₂CHO), -135.8 (d of d's of t's, J_(t) =5.7, J_(d) =66, 112, vinyl CF),-145.1 (t, J=22, CF). IR (CCl₄) featured bands at 1768 and 1837 cm⁻¹ .

EXAMPLE 6

PREPARATION OF CF₃ CH₂ OCF₂ CF₂ CHO

A 3-necked round bottom flask was charged with 10% Pd/C (400 mg) andcooled to 0° C. Triisopropylsilane (6.44 g, 40.7 mmol) was added, andCF₃ CH₂ OCF₂ CF₂ COCl (9.15 g, 34.9 mmol) was added dropwise. Themixture was warmed to room temperature, and the exotherm was thencontrolled by a room temperature water bath. The mixture was stirred anadditional 22 hr over which time an additional 0.2 g of catalyst wasadded. The product was removed by vacuum transfer at 27 Pa. Afterisolation of the lower layer and washing several times with petroleumether at -25° C. there was obtained 4.32 g of colorless liquid. ¹⁹ F NMR(glyme-d₁₀): -74.4 (t of t'2, J=8.2, 21.7), -87.35 (m, OCF₂), -128.27(apparent quartet, J-4 Hz, CF₂ CHO.sub.). GC/MS showed the major productwith a fragment ion of m/z=209.0023. Calcd. for CSH₃ F₆ O₂ (M-F):209.0037.

EXAMPLE 7 PREPARATION OF CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ CHO

A 3-necked round bottom flask equipped with an addition funnel wascharged with 10% Pd/C (1.2 g) and cooled to 0° C. Triisopropylsilane(11.0 g, 70 mmol) was added in one portion and CF₃ CH₂ OCF₂ CHFOCF₂CF(CF₃)OCF₂ CF₂ COCl (30 g, 57 mmol) was added dropwise over a 10 minperiod. The mixture was allowed to warm to ca. 25° C., and the exothermwas controlled by a cool water bath. Conversion of the acid chloride wassubstantially complete at this stage. The last few percent was convertedto product by addition of 0.3 g Pd/C and 1.8 g triisopropylsilane andstirring for 48 hr. Product was removed at 13 Pa while maintaining thereaction vessel at ca. 40°-50° C. The lower layer was isolated afterchilling at -25° C. and additional washing with petroleum ether gave16.5 g of colorless liquid. ¹ H NMR (THF-d₈): 9.64 (m), 6.72 (d of m's,J=52), 4.62 (q, J=8). ¹⁹ F NMR: -74.80 (t, J=8, CF₃ CH₂), -80.0 (m,CF₃), -81.7 to -85.3 (overlapping AB patterns, OCF₂), -89.95 and -90.64(AB patterns, J=145, OCF₂), -127.91 (apparent quartet, J=2.5, CF₂ CHO),-144.7 (apparent t, J=21, CF), -145.9 (d of m's, J=52, CHF). IR (CCl₄)featured bands at 1768 cm⁻¹ (C=O) and 1240-1150 cm⁻¹ (CF). GC/MS showedhighest mass fragment of m/z=471.9844. Calcd. for C₁₀ H₃ F₁₅ O₄ (M-H, F)=471.9791.

EXAMPLE 8 POLYMERIZATION OF CF₃ CH₂ OCF₂ CF₂ CHO WITH TASF IN THF

A sample of the title aldehyde (0.63 g) was treated with a solution ofTASF, tris(dimethylaminosulfonium) trimethyldifluorosilicate, (4 rag) inTHF (2 mL) and cooled to -25° C. for ca. 10 min. After warming to 25° C.NMR analysis (dilution with THF-d₈) revealed a 40/60 mixture ofpolymer/monomer. Further addition of catalyst resulted in similarsolution viscosity, but slow evaporation of solvent provided a soft gel.Size exclusion analysis of the crude product showed a faction (20%) ofmaterial with M_(n) -236,000, the remainder of low molecular weight.Thus in THF solution, TASF treatment of this monomer results in slowreaction and incomplete conversion of monomer.

EXAMPLE 9 POLYMERIZATION OF CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ CHOWITH TASF

A catalyst solution was prepared by treating TASF,tris(dimethylaminosulfonium) trimethyldifluorosilicate, (10 mg) with 10drops of 1,1,2,2,3,3-hexafluorocylcopentane. One drop of the catalystsolution was added to the title aldehyde (0.50 g) and the mixture wasmanipulated with a spatula. After 18 hr, perfluoroallylfluorosulfate(1.0 mL) was added and the mixture was stirred for 1.5 hr.1,1,2-trichloro-1,2,2-trifluoroethane (10 mL) was added, and stirringwas continued for ca. 1.5 hr to afford a viscous solution. After anadditional 1.5 hr, volatiles were removed and product was washed withCH₂ Cl₂ to give 0.46 g of white waxy solid. TGA showed a 10% weight lossbetween 150° C. and 230° C. then a more rapid loss DSC featured Tg at-53° C. Size exclusion analysis showed: M_(w) =395,000; /M_(n) =33,500.¹⁹ F NMR (THF-dS): -75.0 (bd s, CF₃ CH₂), -80.0 and -80.2 (CF₃ +part ofOCF₂), -82.5 to -87.0 (bd, overlapping signals, OCF₂), -90.8 (bd s,OCF₂), -121 to -126 and -132 to -139 (bd, overlapping collection of ABpatterns for CF₂ CH), -145.0 (bd s, CF), and -146 (bd d of m's, CHF). ¹H NMR (THF-d₈ ): 6.5 (d of m's, J=52 Hz, CHF), 5.8 and 5.4 (bd,overlapping signals), 4.5 (bd m, CH₂ CF₃).

EXAMPLE 10 POLYMERIZATION OF C₇ F₁₅ CHO WITH CF₃ CH₂ OTiL₃

Alkoxytitaniumtriethanolamine complexes were prepared as describedbelow. A solution of titanium isopropoxide (28.4 g, 0.1 tool) in toluene(100 mL) was treated with triethanolamine (freshly distilled, 14.9 g).After 3 hr at ambient temperature, the solvent was removed under reducedpressure and the product was triturated with ether, then filtered andwashed with small amounts of ether to provide 23.5 g of white powder(93%), mp 111°-113° C. Anal. calcd. for C₉ H₁₉ O₄ NTi: C, 42.70; H,7.57; N, 5.53. Found: C, 42.18; H, 7.18; N, 5.55. 1H NMR (CD₂ Cl₂): 4.60(sept, J=6, CH), 4.40 (t, J=5.6, CH₂), 3.15 (t, J=5.6, CH₂), 1.20 (d,J=6.0, CH₃) .

A mixture of the above triethanolaminetitanium isopropoxide (9.29 g,36.7 mmol) and toluene (100 mL) was treated with trifluoroethanol (7.34g, 73.4 mmol) and was stirred for 67 hr. The resulting suspension wasevaporated, and the solid was triturated with ether and filtered to give10.08 g of white powder, mp 177°-180° C. ¹⁹ F NMR (CD₂ Cl₂ /25° C.):-76.5 (t, J=9), ¹ H NMR: 4.70 (q, J=10 Hz), 4.57 (m, CH₂), and 3.30 (m,CH₂). Spectra were temperature-dependent.

A sample of C₇ F₁₅ CHO (400 mg) was treated with the title titanate (4mg). The resulting mixture gelled and then became a crumbly white solid.TGA showed the onset of weight loss at ca. 65° C.

EXAMPLE 11 POLYMERIZATION OF CF₃ CH₂ OCF₂ CF₂ CHO WITH EVEOTiL₃

EVEOTiL₃, (CF₂ =CFOCF₂ CF(CF₃)OCF₂ CF₂ CH₂ OTi(OCH₂ CH₂)₃ N), wasprepared as follows: A mixture of triethanolaminetitanium isopropoxide(2.53 g, 10 mmol) and toluene (20 mL) was treated with CF₂ ═CFOCF₂CF(CF₃)OCF₂ CF₂ CH₂ OH(3.94 g, 10 mmol) and stirred for 24 hr at 25° C.The solvent was removed under reduced pressure, and the gummy solid (6.0g) was triturated with petroleum ether, filtered and washed with morepetroleum ether. ¹⁹ F NMR (CD₂ Cl₂): -80.0 (m, CF₃), -83.7 (center of ABpattern, OCF₂), -84.8 (center of AB pattern, OCF2), -113.55 (dd, J=65,84 Hz, CF), -121.7 (dd of m's, J=84, 112, CF), -122.3 (bd s, CF₂ CH₂),-135.6 (dd of triplets, J=65, 112, 5.7, CF), -145.2 (t, J=22, CF).

A sample of CF₃ CH₂ OCF₂ CF₂ CHO (1.0 g, 4.39 mmol) in a small vial wastreated with EVEOTiL₃ (4 mg) and stirred until a gel formed. After 18hr, a hard, white solid was formed. Since depolymerization occurred insolution, NMR and size exclusion analyses were carried out as soon aspossible after product was dissolved in THF. In both, starting aldehydewas clearly evident, and signals due to this component increased withtime. ¹⁹ F NMR: -74.35 (bd s), -85.23 and -87.57 (bd AB pattern, J=140Hz, OCF₂), -123.0 and -136.7 (bd AB pattern, J=282 Hz). Size exclusionanalysis showed a broad distribution of molecular weights ranging fromca. 1.2×10⁶ to 1100.

EXAMPLE 12 POLYMERIZATION OF FLUORINATED ALDEHYDE WITH TITANIUMISOPROPOXIDE

A sample of C₇ F₁₅ CHO (1.00 g, 2.59 mmol) was treated with titaniumisopropoxide (4.0 μL, 1.4×10⁻² mmol) by syringe. The liquid was mixedand allowed to stand for 0.5 hr. The resulting solid was manipulatedwith a spatula and allowed to stand for 0.3 hr. The ¹⁹ F NMR spectrum ofthe product, recorded without solvent (after melting at 130° C.): -82.7(brd s, CF₃), -121.7, -122.0, and -123.0 (singlets, 3 CF₂ groups),-124.0 (s, CF₂), and -126.6 (s, 2 CF₂) was consistent with a single typeof C₇ F₁₅ fragment. Starting material and characterizable ends were notobserved.

EXAMPLE 13 POLYMERIZATION OF CF₃ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ CHOWITH Al (OCH₂ CF₃)₃

Aluminum trifluoroethoxide was prepared by treatment of a toluenesolution of triethylaluminum (0.38M) with these equivalents oftrifluoroethanol at -25° C. After gas evolution was complete, thereaction mixture was allowed to stand at room temperature. Whenprecipitation of product appeared to be well-advanced (1-2 hr), thereaction mixture was cooled at -25° C. for 18 hr before collecting thesolid product. From 1.76 mmol of Et₃ Al and 0.528 g trifluoroethanol wasobtained 435 mg of white solid, mp 171°-172° C. ¹ H NMR (THF-d₈): 4.1(q, J=8). ¹⁹ F NMR (THF-d₈): -77.0 (bd s), trace signals at -76.3 and-77.7.

A sample of the title aldehyde (0.50 g) was treated with aluminumtrifluoroethoxide (0.2 mg). The resulting solution formed a clear gel,and this was allowed to stand for 18 hr. ¹⁹ F NMR analysis showed thatthe product readily reverts to starting aldehyde in THF-d₈.

EXAMPLE 14 ENDCAPPING WITH FLUORINE

A 1.0 g sample of polyacetal obtained in a similar manner as Example 13by reaction of CF₂ CH₂ OCF₂ CHFOCF₂ CF(CF₃)OCF₂ CF₂ CHO and Al(OCH₂CF₃)₃ was cut in small pieces and placed in a Hastelloy® cylinder whichwas evacuated and then pressurized at 3.7×10⁵ Pa with an 80/20 mixtureof N₂ /F₂. After 10 days, excess F₂ was removed and the solid was washedthoroughly with aqueous sodium bicarbonate to give 0.97 g of whitesolid. TGA analysis showed 20% weight loss between 120° and 275° C.Removal of the unstabilized material by heating under vacuum at 195° C.for 1.5 hr gave a white solid exhibiting good stability to 285° C. Thismaterial was not soluble. It exhibited a Tg at -50° C.

Although preferred embodiments of the invention have been describedhereinabove, it is to be understood that there is no intention to limitthe invention to the precise constructions herein disclosed, and it isto be further understood that the right is reserved to all changescoming within the scope of the invention as defined by the appendedclaims.

What is claimed is:
 1. A polymer, comprising, the repeat unit ##STR8##wherein: Y is fluorine, aryloxy or --OCF═CF₂ ;each X is independentlyhydrogen or fluorine; p is 0 or 1; and k, m and n are each independentlyzero or an integer of 1 to 50; provided that k+m+n is 2 or more.